It is known to place a humidifier at the output of a respiratory assistance device that delivers air to a user, so as to humidify the air supplied to the user and thus avoid drying out of the respiratory tract.
In order to obtain sufficient air humidification over the entire range of possible air flow rates (between 0 and 2 L/s), it is prescribed to heat the air contained in a humidifier reservoir, so as to accelerate evaporation and therefore transfer the water molecules to the air delivered to the user.
For the comfort of the user, the humidifier should be able to permit control of the degree of humidification of the supplied air.
Regulation systems of such heating humidifiers are already known that seek to supply the user air having a desired humidity level, for example, an essentially constant humidity level.
A first known system consists of regulating only the water temperature. Hence, the degree of humidification of the air delivered to the user also depends on the temperature of the air, which can vary, especially between day and night. It follows that simple regulation of the water temperature may not permit a constant air humidification level, which may be unsatisfactory.
A second known system employs, on the one hand, a temperature probe for the water, and, on the other hand, a temperature probe for the air. This system has higher performance, because it accounts for ambient conditions. However, such a system requiring the use of two probes may be relatively costly and more complex to use.